Modernizing persistence-bioaccumulation-toxicity (PBT) assessment with high throughput animal-free methods.

Area of Science:

• Environmental Chemistry
• Toxicology
• Chemical Safety Assessment

Background:

• Current methods for assessing chemical persistence (P), bioaccumulation (B), and toxicity (T) under regulations like REACH are complex, inefficient, and often rely on animal testing.
• These traditional approaches can lead to inaccurate conclusions and hinder the timely evaluation of chemical safety.

Purpose of the Study:

• To introduce novel hazard indicators, cumulative toxicity equivalents (CTE) and persistent toxicity equivalents (PTE), as replacements for existing PBT assessment methods.
• To propose a high-throughput, in vitro-based workflow for evaluating chemical hazards, including the emerging concept of mobility (M).

Main Methods:

• Development of two new hazard indicators: CTE (direct toxicity measurement) and PTE (toxicity after simulated environmental degradation).
• Utilizing high-throughput in vitro bioassays to measure CTE and PTE, avoiding the need for analytical identification of transformation products or mixture components.
• Integration of P, B/M, and T assessment into a single experimental workflow.

Main Results:

• CTE and PTE provide a comprehensive measure of toxicity and its persistence or degradability.
• The proposed indicators can be measured using animal-free in vitro assays, significantly reducing reliance on animal testing.
• The methodology offers a streamlined approach to hazard assessment, applicable to single chemicals, substitution products, and mixtures.

Conclusions:

• CTE and PTE represent a significant advancement in chemical safety assessment, offering a more efficient and ethical alternative to traditional PBT methods.
• These indicators support the European Union's Chemicals Strategy for Sustainability by providing robust data for regulatory decision-making.
• The proposed workflow facilitates high-throughput screening and integrates key hazard parameters, enhancing the overall safety evaluation of chemicals.